I believe I have had positive encounters with the spirit realm but there is of course no way to objectively prove it.
But we all believe in non-paranormal experiences that we have not personally experienced. As I enjoy studying the paranormal I look at the quantity and quality of experiences and look for patterns, consistency, etc. and form my best opinion. I would know very little about anything normal or paranormal from just my own experience.
Fair enough...
That's why I remain fairly uncertain about things beyond my experience. There's a lot I remain uncertain about